Sifting apparatus



Sept.,l1,1$45. R. v. WARD 1 SIFTING APPARATUS Filed June 17. 19,42]

. 'INVENTOR. Boy/4x. 1 W120,

v ATTORN V Patented Sept. 11, 1945 i um'rso STATES PATENT OFFICE A 2,384,715 V j SIFTING APPARATUS Royal V. Ward, San Bernardino,Oalif. Application June 17, 1942, Serial No. 447,339 14 Claims. 01. 209-2375 This invention relates to and has for an object the provision of an improved sifting apparatus by means of which analyses and tests may be madeof comminuted material, sand, gravel and other matter, and in which a motor driven means is provided for simultaneously operating a plurality of sifters in such a manner that the more finely divided elements will be gradually moved downwardly by gravity and agitation from the topmost sieve of the stack to the lowermost tray.

A particular object is to provide an apparatus for the purpose described which embodies a novel and highly effective sifting means capable of prodllclng primary oscillations of the stack of sieves or trays as well as secondary or counter oscillations thereof, so that the primary oscillations will efiect the sifting of the material in the manner usually accomplished by hand or machine driven elements while the counter oscillations will prevent the piling or stacking of the material at the margins of the trays and thereby serve to maintain a substantially uniform level of the material at all times.

Other objects may appear as the description progresses.

I have shown a preferred form of apparatus embodying my improvements in the accompanying drawing, subject to modification, within the scope of the appended claims, without departing from the spirit of my invention. In said drawing:

Fig. 1 is a side elevation of an assembled machine;

Fig. 3 is an elevation of the same as seen at right angles to the plane of Fig. 1;

Fig. 2 is a top plan view of the same;

Fig. 4 is a sectional plan on line 44 of Fig. 1; and

Fig, 5 is a sectional plan on line 5-5 of Fig. 1.

Ina preferred form' of apparatus capable of economical production, as herein shown,'the machine is supported on a base I having a vertically disposed column 2 extended therefrom towhich is attached a vertical standard 3 hereinshow'n as of right angular cross section. Said standard is rigidly secured to column 2 as by means of bolts 4, 4, and a motor 5 is supported on the column 2 as by means of a .b-racket'li extended laterally from the column and suitably secured thereto.

Standard 3 has a pair of vertically spaced arms I and 8 rigidly attached thereto at its top and bottom portions which serve to rotatably support a tubular spindle 9 as by means of suitable bearings Ill and II, respectively. A pair of arms 12 and [3 are carried by spindle 9, at the bottom and top respectively, for the purpose of operatively supporting a plurality of sifting trays, as shown in Fig. 1, as at l4, [4 etc which are mounted sothat each one nests within the next lowest unit and said lowest tray similarly nests in a screenless tray, as at H5, at the bottom of the stack for receiving the final products of each sifting operation for the purpose of analysis and test. Usually the top of each tray 14 and I5 has a bead H5 (Fig. 1) around its upper lip with'a recess therewithin to receive the bottomof the next adjacent tray and thereby prevent the dislodgement of the trays from their nested positions'duringthe sifting operations, and the uppermost tray carries a cover Ma;

Thestack of trays l4 and I5 are oscillatably held on anarm H- which is fixed at an end to a tubular spindle I8 which, in turn is pivotally supported in bearings 19 and 20 on the free ends of arms [2 and 13. The lowermost tray 15 seats on arm ll between a pair of lugs 2| and 22 and diametrically spaced lugs 23 and 24 on the extremities of a bar 24' attached by suitable means to arm H, as shown in Fig. 4.

The free end of arm I'l carries a pair of fingers 25 and 26 which are attached to the edges of the arm by means of bolts 21 and 28, respectively, and preferably so that the fingers may be selectively spaced from the arm H, as by means of one or more washers 29 held between the fingers and the arm. As shown in Fig. 4, fingers 25 and 26 straddle the spindle 9 so that during the primary oscillation of the trays, as hereinafter explained, said fingers will strike opposite sides of the spindle and set up counter or secondary oscillations in the movement of the trays. The topmost tray [4 has a cover Ma for preventing the lossof material from said tray during successive'sifting operations.

One of the upper trays-or more if necessary, may beadditionally supported against dislodgement from the stack as by means of a band 30 extending partially around the tray and provided at its ends with attaching members 3| extended through slots 32' in opposite portions 33 in a fixture 34 which-is vertically adjustable on spindle land adapted to be heldin selected position by meansof a set screw 35- or otherwise. Each of the trays .I4 is provided with a screened bottom 36 which plurality of screens in the stack of trays or sieves are of gradually decreasing mesh from the top downwardlyin order that the final and most finely. divided elements of the material introduced into the topmost tray .will be gradually sifted to the receiving tray 15 while the larger particles will be likewise gradually and from stage to stageeliminated. i A

and secondary movements of the sifting elements may be effected, the geometric axis of the siftin elements being off-set from the axes of oscillation of the frame and the support.

8. A sifting apparatus comprising: a frame, means for oscillating the frame, oscillatable both with and independently of the frame on different axes, a sifting means carried by said support and. having a geometric axis intermediate the axes of the frame and the support, whereby primary and secondary movements of the sifting means may be effected, and means for limiting the movement of the sifting means relative to the frame.

9. A sifting apparatus comprising: a base having an upright member thereon, a frame oscillatable on said member, a support oscillatable with said frame on said member and separately on said frame, and sifting elements carried by said support, and means for oscillating said frame, whereby counter oscillations of the support and the sifting means is effected.

10. A material sifting apparatus including: a stationary frame, a secondary frame mounted on said stationary frame for oscillation about a first vertical axis, a support oscillatably mounted on a second vertical axis on said secondary frame spaced from and substantially parallel to said first axis and adapted to support a stack of sifting elements and effect counter oscillations of the stack of sieves, the geometrical axis of the sifting elements being substantially parallel to and spaced from said first and second axes.

11. A material sifting apparatus as characterized in claim 10, including means for oscillating the secondary frame.

12. A material sifting apparatus as characterized in claim 10 including means for separately oscillating the secondary frame and the support.

13. A material sifting apparatus as characterized in claim 10 including means for limiting the counter oscillations of the support and the sifting elements carried thereby.

14. A material sifting apparatus compris ng: a main frame, a secondary frame oscillatable thereon, a support oscillatably held on the secondary frame and having an axis remote from the oscillating axis of the secondary frame, said support adapted to carry a stack of sifting elements, and means for applying power to and for setting up oscillations of the secondary frame and counter oscillations of the support and the sifting elements, said secondary frame and said support having separate axes of oscillation which are offset relative to the geometric axis of the s fting elements.

R. V. WARD. 

